Twenty years ago, Susan Rothrock planted a 12-inch stalk of bamboo in her backyard thinking it would grow and make a nice shield between her and her neighbor's properties in Drexel Hill.

"Grow" is too mild a way to describe what happened next. The dense grove of bamboo in Rothrock's backyard today looks as if it could support a family of pandas.

Her neighbor has complained repeatedly to Upper Darby Township, worried that the pesky plant will invade her backyard, too.

"If I had any idea it was going to create this kind of problem, I wouldn't have planted it," said Rothrock, a 71-year-old widow.

As many gardeners know, bamboo - the running, not the clumping kind - spreads relentlessly and can cause havoc, breaking up sidewalks and creeping into basements. It also promotes problems between neighbors as the invasive plant plows through anything in its path.

Now Upper Darby is considering an ordinance to ban the lovely and lush plant that sways gently in the breeze and provides almost instant privacy but is fast becoming a scourge of the suburbs. Many municipalities throughout the Northeast have already outlawed bamboo, which grows up to 40 feet a year, has roots like steel, and defies efforts to eradicate it.

"It can uproot sidewalks and curbs," said Tom Judge Jr., chief administrator for Upper Darby, whose proposed ordinance would forbid new plants and restrict existing ones from being closer than 40 feet to roads or pavement and impose a $1,000-a-day fine for violations. Haverford, Nether Providence, Swarthmore, and Rutledge already have similar ordinances, he said.

No wonder. Bamboo and Japanese knotweed, another fast grower, are all over the place, forester Clyde Hunt said. In early spring, he visited a park with bamboo shoots two to three feet high. A week later, they were seven feet. Now they are 18 feet tall and tangled in telephone wires.

"The roots are a hotbed of stored energy," said Hunt, who is helping educate residents about the dangers of bamboo.

A house in Lansdowne is almost completely shielded by the spiky stalks, with just a chimney and third-floor attic peeking over the branches, Hunt said.

The Institute of Invasive Bamboo Research, started by a Connecticut woman who sued her neighbors over their bamboo, has noticed Upper Darby's bamboo problem and posted pictures of some overgrown sites on its Facebook page.

Founder Caryn Rickel said a field researcher was visiting the township when she saw the invasion and read about the proposed ban.

Anti-bamboo laws "are ripping through states," she said.

Bamboo is also strangling parts of Chester County, where about six communities, including Warwick, London Grove, West Nottingham, and North Coventry, have restricted the plant, said Glenn Bentley, a land-development planner.

"It grows at the exclusion of everything else," he said. "Nothing else can survive where bamboo survives. It's impervious to a lot of natural and man-made interventions for removing it."

In other words, it's practically indestructible. Just ask Randy Bothwell, a detective with the Chester Police Department.

After using a machete and pickax to cut and dig up the roots of the bamboo in his yard, Bothwell got serious: He rented a mini-bulldozer and bought 14 gallons of herbicide and 24 cubic yards of dirt.

He jokingly wrote on a blog that he even considered exorcism and shooting the plant with his revolver.

But two weeks after his massive dig, he returned from vacation to find a single bamboo shoot. Today, he said, his yard may be awash in toxic chemicals, but it is bamboo-free.

Linda Barry, the master gardener coordinator for Penn State Extension in Delaware County, said a friend had to rent a backhoe to dig out bamboo that had invaded his basement.

"It's very expensive to get rid of," she said.

Since it grows so fast, pruning is a waste of time. "You cut it back, and you can practically watch it grow," she said.

Not all bamboo causes havoc.

There are two primary types that grow in the United States, known as clumping and running bamboo.

As the names suggest, clumping is not a problem. But running bamboo has roots that tunnel far from the plant and grow new shoots.

"It will come out on the other side of your driveway," Hunt said.

Running bamboo will escape most barriers. It doesn't compost or break down and doesn't chip well for mulch. Even deer, which treat most gardens like mouth-watering buffets, don't seem to like it.

Digging out the roots, or rhizomes, completely is one of the only ways to get rid of the plants, and that is a difficult and expensive task.

The roots can be contained with a rhizome barrier, a high-density polyethylene that needs to be dug deep underground.

"It's hard work," said Jim Shannon, who owns Bamboo Habitat in Perkiomenville, where he grows and sells bamboo products, including the barriers.

Half of his customers, he said, are people "planting bamboo responsibly by putting in barriers, and the other half are people whose neighbors are growing bamboo and causing a problem."

Another way to contain the roots is by digging a trench, said Penn State's Barry.

One website advises digging a trench 36 inches deep and 10 inches wide and placing polyethylene plastic sheeting in it secured with aluminum strips.

Then fill all that with sand.

Even then, the site cautions, "the rhizomes need to be watched and checked to make sure they do not breach the barriers."